Assessment of spatial variations in water quality of Garra River at Shahjahanpur,Ganga Basin,India

Arabian Journal of Geosciences - A comprehensive study on the chemical considerations of thermal waters (springs and geothermal wells) on the performance of solute geothermometers in predicting the...     

Facies analysis and sequence stratigraphy of Kometan Formation (Upper Cretaceous) in the imbricated zone,northeastern Iraq

Facies and sequence stratigraphic analysis of the Kometan Formation (Upper Cretaceous) were studied from Kometan village, Kurdistan region of northeastern Iraq. Lithologically, the formation consists of 44 m of white weathering, light grey, thin to medium-bedded highly fractured limestones with chert nodules. Petrographic study of the carbonates shows that both skeletal and non-skeletal grains were present. The skeletal grains include a variety of planktonic foraminifera (including Oligostegina), calcispheres, ostracods, pelecypods, larva ammonite, and echinoderms. Non-skeletal grains include peloids only. Three main microfacies types are distinguished in the studied formation. The results of stable carbon and oxygen isotopes of the studied carbonate samples show negative values of δ¹⁸O. These indicate that the seawater was warm with low salinity during precipitation of the carbonates in the Kometan Formation in northeastern Iraq. The positive δ¹³C values of carbonate samples, in the middle part of the formation, reflect the widespread deposition of organic-rich marine sediments during a transgression and deepening of the basin. Petrographic, facies and stable isotopic analyses revealed that the Kometan Formation was deposited in a warm, basinal, pelagic (open marine) environment with low salinity. The Kometan Formation consists of one complete third-order depositional sequence, separated by a sequence boundary (SB) of type 2. The third-order sequence is subdivided into a transgressive systems tract (TST) and highstand systems tract (HST). This reflects episodes of transgression and still stands of the relative sea level. The TSTs are topped by maximum flooding surface (MFS) characterized by deepening-/fining-upward parasequences implying a retrogradational stacking pattern. The HST is marked by shallowing-/coarsening-upward parasequences implying a progradational stacking pattern.     

Automatic identification of fake patterns caused by short-width wavelets in seismic data

Despite the popularity of using the Haar wavelet filter in many applications, it sometimes introduces fake patterns into the multi resolution analysis (MRA) of seismic data. In this work, we compared different wavelet filters to demonstrate that these patterns are fake and not part of the original waveforms and to show that they are a result of using the Haar wavelet filter as a short-width wavelet. To achieve this, many seismic waveforms from two different sources: the Egyptian National Seismic Network (ENSN) and the High Sensitivity Seismograph Network Japan (Hi-net) are used with different wavelet filters. We propose an algorithm based on an autoregressive (AR) model to detect these patterns automatically and fully.     

<Emphasis Type="Italic">H-M</Emphasis> bearing capacity of a modified suction caisson determined by using load-/displacement-controlled methods

This paper presents a series of monotonically combined lateral loading tests to investigate the bearing capacity of the MSCs (modified suction caissons) in the saturated marine fine sand. The lateral loads were applied under load- and displacement-controlled methods at the loading eccentricity ratios of 1.5, 2.0 and 2.5. Results show that, in the displacement-controlled test, the deflection-softening behavior of load-deflection curves for MSCs was observed, and the softening degree of the load-deflection response increased with the increasing external skirt length or the decreasing loading eccentricity. It was also found that the rotation center of the MSC at failure determined by the load-controlled method is slightly lower than that by the displacement-controlled method. The calculated MSC capacity based on the rotation center position in serviceability limit state is relatively conservative, compared with the calculated capacity based on the rotation center position in the ultimate limit state. In the limit state, the passive earth pressures opposite the loading direction under load- and displacement-controlled methods decrease by 46% and 74% corresponding to peak values, respectively; however, the passive earth pressures in the loading direction at failure only decrease by approximately 3% and 7%, compared with their peak values.     

Spatial multi-criteria analysis for selecting potential sites for aquifer recharge via harvesting and infiltration of surface runoff in north Jordan

In (semi-)arid regions, available water resources are scarce and groundwater resources are often overused. Therefore, the option to increase available water resources by managed aquifer recharge (MAR) via infiltration of captured surface runoff was investigated for two basins in northern Jordan. This study evaluated the general suitability of catchments to generate sufficient runoff and tried to identify promising sites to harvest and infiltrate the runoff into the aquifer for later recovery. Large sets of available data were used to create regional thematic maps, which were then combined to constraint maps using Boolean logic and to create suitability maps using weighted linear combination. This approach might serve as a blueprint which could be adapted and applied to similar regions. The evaluation showed that non-committed source water availability is the most restricting factor for successful water harvesting in regions with <200 mm/a rainfall. Experiences with existing structures showed that sediment loads of runoff are high. Therefore, the effectiveness of any existing MAR scheme will decrease rapidly to the point where it results in an overall negative impact due to increased evaporation if maintenance is not undertaken. It is recommended to improve system operation and maintenance, as well as monitoring, in order to achieve a better and constant effectiveness of the infiltration activities.